Interlocked duplex broaching machine



3 Sheets-Sheet l CHINE K. C. MONROE INTERLOCKED DUPLEX BROACHING Filed Feb.' 23, 193

Dec. l2, 1939.

l f l 1 l l f l l 1 l 1 l l l l l 1 l l l l l l f m l l u vamp Dec. l2, 1939. K. c. MONROE I NTERLOCKED DUPLEX BROACHING MACHINE Filed Feb. 23, 1938 3 Sheets-Sheet 2 Per wt? w TLM 3 Sheets-Sheet- 3 Dec. 12, 1939. K. c. MONROE INTERLCKED DUPLEX BROACHING MACHINE Filed Feb. 23, 1938 Patented Dec'. 12, 1939 INTERLOCKED DUPLEX BROACHING MACHINE Kenneth C. Monroe, Hudson, Mass., assignor to The Lapointe Machine Tool Company, Hudson, l Mass.,a corporation of Maine Application February 23, 1938,y Serial No. 192,118

9 Claims.

This invention relates to duplex breaching machines which are hydraulically operated and in which two breaching rams or slides are` moved alternately and simultaneously in opposite directions.

It is the general object of my present invention to provide actuating mechanism and control devices forsuch a breaching machine, so.

designed and correlated that the machine may 10, be conveniently controlled and operated, but only according to a predetermined sequence of steps.

More specically, I provide control devices so interlocked that the werk clamping devices, the

fixture slideand oneer the other of the breaching rams must all be in correct operative relation before a Working stroke of said ram can take place.

My invention further relates to arrangements and combinations of parts which will be herein- '|20 after described and more particularly A`pointed out in the appended claims.

A preferred ferm of theinvention is shown in the drawings, in which Fig. 1 is a diagrammatic plan .view of my improved breaching machine, with certain partsr in section and with the machine at rest and in loading position;

Figs. 2 and 3 are partial diagrammatic Views showing the relationv of certain parts at successive points in the cycle @Y of machinek operation;

ing rams or slides A and B connected to pistons 20 and ZI slidable in main cylinders 22 and 23.

These cylinders are connected bypipes 2li and 25 to a pump =P which is of the reversible discharge type, such as is shown for instancel inthe patent to West No. 1,722,832. n v

The direction vand rate of discharge of the pump P is controlled by a pinion 26 and rack 21,

and the rack is connected to a main control lever .28 pivoted at 29 and having a handle 30 Aby which it may be manuallyA operated. Thelever 28 is also connected to Aa piston 3| in a main control cylinder 32.

A knock-eff rod 33 is connected through a lever 3ll and link 35 to the jcontrol leverr28 and is Fig. 4 is a View similarto Fig. l but showing (e1. ca -ss) provided with an adjustable knock-oilv collar 36 adapted to be positioned for engagement by an arm 3l on the ram A as the ram approaches the end of its downward er working stroke. By such engagement, the control lever 28 is returned to `5 mid or neutral position, in which position there is no discharge of the pump P in either direction. A second knock-olf rod 38 is connected by a lever 39 and link #i0 to the extended end of the control lever 26 and is provided with an adjust- 10 able collar M positioned for engagement by an arm i2 on the ram B as said'rarn'B approaches the end of its downward or yworking stroke. The lower ends of the cylinders 22 and 23 are connected by a pipe #i3 having a needle valve 15 53a by which back pressure is provided and controlled. v

A solenoid operated valve V is'provided for the control cylinder 32, and liquid under pressure is supplied to the valve V by anauxiliary pump 20 P',r the surplus discharge vfrom which is returned to a reservoir R through a relief valve 44. rThe discharge from the control cylinder 32 is vdelivered to the reservoir R. through an exhaust pipe 45, and the rate of movement of the valve `25 is controlled by a needle valve 46.

A fixture slide 53 is associated with a fixture slide cylinder 5I mounted to slide on a fixed plston rod 52 and relative to a fixed piston' 52a. The xed piston rod 52 is hollow at both ends 30 but closed where the piston is mounted and is*y provided with ports adjacent kthe piston which open into'the opposite ends of ycylinder 5l. The cylinder 5I and slide 5b are movable from a right-hand tov a left-hand werking position or 35 vice-versa in accordancewith the application of pressure to one end or the other of the fixed piston rod 52.` K

Oil underl pressure is supplied 'to the vhollow rod 52 through pipes 53 and 54 which are con- 40 nected to a valve V which in turn receives oil under pressure from aI pump P2 through a pipe v 55. ,Excess discharge of the pump P2 is returnedv to the reservoir R-through a relief valve 56, and I the rate of flow through the pipe 55 to the cyl- 45 inder 5l may be controlled by aA needle valve 51. Backqpressure in the idle end of the cylinder 5| is provided by a relief valve 58. y

The fixture slide valve V is providedwith a handle by whichv it may be manually oper- 50 ated. The handle 5D is, however, normally locked Y in one position orthe other by a plunger 6| slidable in a solenoid coil 52. When the solenoid is energized, the plunger is withdrawn and the valve may be shifted but when the solenoidl cir- 55 cuit is open, the handle 6l! and Valve V are locked against manual movement. The control of the solenoid 62 will be hereinafter described.

The two ends of the xture cylinder 5I are connected through check valves 64 and 65 to a valve V2 which in turn is connected through pipes E6 and '51 to the opposite ends of a work clamping cylinder 68 in which a piston 69 is slidable. The piston 69 is connected to the work-clamping devices (not shown) and these clamping devices are free when the piston 69 is in raised position, as shown in Fig. 1. The work is clamped when the piston 69 is in the lowered position shown in Fig. 2. The valve V2 is manually operated by a handle 10. Back pressure on the piston 69 is provided by a needle valve 1|.

The valve V2 and work clamping devices including the clamping cylinder 68 are all mounted to move with the fixture slide 50 and cylinder 5|. This construction has the great advantage that oil under pressure is not transmitted through connections between relatively moving parts. Outside connections are made only through the fixed piston rod 52.

Having described the main features of my improved broaching machine and the hydraulic actuating mechanism therefor, I will now describe the interlocking electrical connections by which the sequence of operations is predetermined.

Fixture switches 80 and 8| are provided, which switches are normally open but are closed alternately by the xture slide 58 when the slide is in one or the other of its right-hand and left-hand working positions. Limit switches 82 and 83 are closed only when engaged by cam plates 84 and 85 on the broaching rams A and B, when one or the other of the rams is in upper or withdrawn position at the end of its return stroke.

The limit switch 82 is a double pole switch separately controlling one circuit through the xture switch 89 and a second circuit through a solenoid coil 86 which may be energized to raise a plunger 81 to clear a plate 88 on the side of the handle 10.

The fixture switch 8l is also a double pole switch, one part of which controls a circuit through the solenoid operated valve V. The second part of the switch 8| is in series with one part of the switch 82 in the circuit of the solenoid 85.

Current is derived from line wires 9!) and 9|, and a manually operated switch or push button 92 is inserted in the line 9|. An additional switch 94 is associated with the work clamping cylinder 68 in such manner that the switch 94 is open when the piston 69 is raised and the work is released, but is closed when the work is clamped.

The parts are shown in Fig. 1 in work-loading position, with the ram A raised, the ram B lowered, the xture slide in right-hand or loading position, and the piston G9 raised so that the work-clamping devices are open or withdrawn.

The double pole limit switch 2 is closed by the cam plate 841 and the double pole iixture switch 8| is closed by the fixture slide 50. The main control lever 28 is in mid position and the pump P is in no-discharge position.

After the work has been placed on the fixture slide 50, the operator moves the handle 1!) from the position shown in Fig. I to the position shown in Fig. 2, reversing the pressure connections to the cylinder 68 and causing the piston 89 to move downward and clamp the work. As this downward movement takes place and the work is clamped, the switch 94 is closed.

The operator then closes the manual switch 92,

thus completing the circuit through the switch 92, solenoid 62 and switch 94, and withdrawing the locking solenoid plunger 6 I. This releases the valve lever 6D. The operator thereupon moves the lever G8 from the position shown in Fig. 1 to the position shown in Fig. 3, thus reversing the connections in the valve V and applying pressure in the left-hand end of the fixture cylinder 52, thus moving the xture slide 50 to the lefthand position shown in Fig. 3, which is its working position in relation to the ram A. As the slide 50 reaches its extreme left-hand position, it engages and closes the switch 80. The switch 8l opens as the fixture slide moves to the left, breaking the circuit through .the solenoid coil 86 and releasing the plunger 81 which moves down and locks the handle 10 against movement to unclamp the work.

The closing of the switch 88 by the fixture slide 58 and the previous closing of the limit switch 82 by the cam plate 84, in conjunction with maintaining the switch 92 closed by the operator, cornpletes the circuit through the solenoid operated valve V, thereby causing the valve to shift its connections to operate as shown in Fig. 3, supplying oil under pressure to the upper end of the control cylinder 32 and shifting the main control lever 28 to the position shown, in which the pump P supplies oil under pressure to the upper end of the main cylinder 22, thus causing the ram A to move downward on its operative or broaching stroke. As soon as the ram A starts to move downward, the operating circuit of the solenoid in the valve V is broken by the opening of the switch 82 and the valve returns to mid or neutral position but the lever 28 remains in the position of Fig. 3. The operator can now release his pressure on the switch 92 as the circuit of the solenoid E2 is also broken by the opening of the switch 82 and the lever is locked in the position shown in Fig. 3.

At the end of the down stroke of the ram A, the arm 31 will engage the knock-off collar 36 and will move the main control handle 28 back to the neutral or no-discharge position shown in Fig. 1. At the same time the cam plate 85 on the ram B will engage and close the limit switch 83, but the reverse operating circuit for the control valve V is not completed, as the fixture slide 50 it still in left-hand position and the switch 8l is open.

The operator now closes the hand switch 92, thus releasing the handle 60, which is then moved manually to reverse the connections of the fixture slide valve V' as shown in Fig. 4, thereby admitting oil under pressure to the right-hand i" end of the cylinder 52 and moving the fixture slide 50 toward the right.

As this movement is completed, the slide engages and closes the switch 8l, thus completing the reverse circuit for the solenoid operated Valve V. The valve Vis thereon shifted to admit oil under pressure to the lower end of the control cylinder 32, moving the main control lever 28 and rack 21 to the position shown in Fig. 4, and thereby causing the pump P to deliver oil under pressure to the upper end of the cylinder 23, thus giving the ram B a downward or operative broaching stroke.

As soon as this movement is begun, the cam plate 85 moves away from the switch 83, which automatically opens, breaking the circuit through the solenoid operated valve V, and also deenergizing the solenoid 62. The plunger 6| then locks the lever 60, now back in the position shown in Fig. 1. During all of these operations, the lever l which controls the clamping devices islocked in theV position shown in Figs. 2 ande and the work cannot be unclamped. 1 i v When the working stroke of the-ram B iscompleted, the arm @2 engages` the knock-olfA collar 4l and restores the control lever 28 and rack 2l; to neutral position, the solenoid circuit, ofythe valve Vv having been previously opened as described, and the valve Vbeing v in neutralposif return to the positionshown in Fig. 1. .This

opens the switch 94 and releases the Work-clamping devices.

The parts are now restored to their initial position, with the ram B at the bottom Of-its Working stroke and with the fixture slide 5i? in its right-hand position for removal of the nished Work and insertion of a new piece of work therein.

Having thus described the construction and cycle of operations of my improved interlocked yduplex hydraulic broaching machine, the advanr tages thereof will be readily apparent. The lever I clamped in the fixture slide.

til cannot be unlocked until the work has been clamped on the fixture slide .by means of the handle lll, thereby closing the'switch 94.

After the work has been clamped, the handle 60 can only be released by closing the hand switch 92, after which the valve V can be manually reversed, causing the iixture slide 50 to move to its left-hand position. As this position is reached, the switch 8i? is closed, thereby causing the ram A to make its working stroke and to thereafter come to rest.. The handle 80 can then be released by again closing the switch 92. By again manually moving the valve V', the iixture slide can be moved to the right-hand position for a broaching operation by the ram B.

During all of this time, the work must remain clamped in the fixture, as the handle Il) can only be released from its clamping position when the ram A is up and the fixture slide is in right-hand ,y

or loading position.

The interlocking control devices above described safeguard the broaching machine, the breaches and the. work itself, as they prevent any improper sequence of operation of the hydraulically actuated means, and prevent the machine from operating at all if the Work is not clamped or if the iixture slide is not correctly and accurately positioned. By the use of my improved machine with its interlocking control devices, I am able to carry out progressive broaching operations on a piece of work, with certain operations performed by the action of one ram and other operations performed by the action of the other ram and with all of the operations performed while the work remains securely I am thus able to economically produce very accurate work, utilizing both rams of a duplex hydraulic broaching machine.

Having thus described my invention and the advantages thereof, I do not wish to be limited to the details herein disclosed, otherwise than as set forth in the claims, but what I claim is:

.1. A duplex broaching machine comprisinga pair of alternately operative and oppositely moving broaching rams, a iixture slide, a device to clampa piece of work thereon .when said slide is' in loading position, means to move said slide transversely to present said piece of work vwhile clamped thereon successively. in operative relation to bothof said rams and to return said work to loading position, and control devices operatively interlocking said rams, slide and clamping device, so that no movement of said rams or slide .can occur until the clamping device has been rendered operative.

"2. A duplex broaching machine comprising a pair oi alternately operative and oppositely moving broaching rams, a fixture slide, a device to clamp a piece of work thereon when said slide is inioading position,vmeans to move said slide Atransversely to present said piece of work while clamped thereon successively in operative rela'- tion to both of said rams and to return said Work to loading position, and control devices operatively interlocking said rams, slide and clamping device, so that thefixture slide can be moved only with the work clamped and with the rams in predetermined positions.

3. A duplex broaching machine comprising a pair of alternately operative and oppositely moving broaching rams, a fixture slide, a device to clamp a piece of work thereon when said slide is in loading position, means to move said slide transversely to present said piece of work while clamped thereon successively in operative relation to both of said rams and to return said work to loading position, and control devices operatively interlocking said rams, slide and clamping device so that the Work cannot be unclamped until a cycle of successive broaching movements by both rams has been completed.

4. A duplex broaching machine comprising a pair of alternately operative and oppositely moving broaching rams, a fixture slide, a device to clamp a piece of 'work thereon when said slide is in loading position, means to move said slide transversely to present said piece of work while clamped thereon successively in operative relation to both of said rams andto return vsaid work to loading position, and control devices operatively interlocking said rams, slide and clamping devicev so that the work cannot be unclamped until the rams and slide have been returned to loading position.

5. A duplex broaching machine comprising a pair of alternately operative and oppositely moving broaching rams, a fixture slide, a device to clamp apiece of work thereon when said slide is in loading position, means to move said slide transversely to present said piece of work while clamped thereon successively in operative relation to both of said rams and to return saidwork to loading position, and control devices operatively interlocking said rams, slide and clamping device, so that the fixture slide can be moved transversely only when the Work is clamped.

6. A duplex broaching` machine comprising a pair of alternately operative and oppositely moving broaching rams, a fixture slide, a device to clamp a piece of work thereon when said slide is in 'loading position, means to move said slide transversely lto present said piece of work While clamped thereon successively in operative relation to both of said rams and to return said work to loading position, and control devices operay tively interlocking said rams, slide and clamping device, so that the clamping device must be rendered operative before either ram can be moved from its limit of travel.

7. A duplex broaching machine comprising a pair of alternately operative and oppositely moving breaching rams, a fixture slide selectively movable transversely to operative relation with a selected ram, a cylinder secured to said slide, and a fixed piston and piston rod relative to which said cylinder is slidable, said piston rod having separated passages in its two ends each connected to admit oil under pressure to one end of said cylinder and at one side of said xed piston.

8. In a duplex breaching machine, a xture slide movable to two selective operative positions, a hydraulic cylinder and piston cooperating `to move said slide, a work-clamping cylinder mounted on said slide, a control valve for said latter cylinder, and connections open continuously from both ends of said fixture slide cylinder to the intake of said control valve, whereby pressure is maintained on said control valve whenever pressure exists in either end of said cylinder.

9. In a duplex broaching machine, a fixture slide movable to two selective operative positions, a hydraulic cylinder and piston cooperating to move said slide, a work-clamping cylinder mounted on said slide, a control valve for said latter cylinder, and connections open continuously from both ends of said xture slide cylinder to the intake of said control valve, said connections being branched to the two ends of said iixture slide cylinder and each branch having a check valve opening away from said cylinder, whereby pressure is maintained on said control valve whenever pressure exists in either end of said cylinder.

KENNETH C. MONROE. 

